Chapter III Historical Weather

1. Definition of weather: cloudy, sunny, rainy, snowy, cold, hot and other atmospheric conditions in a short time. 2. Weather characteristics:

1) The weather reflects the atmospheric conditions of a place in a short time, which is constantly changing.

2) At the same time, the weather in different places is different: for example, "It's raining now" at a certain moment, "It's sultry today" at a certain day, and "It has been raining for several days".

Hey. " 3) The weather is different in the same place at different times. Such as "East Rising and West Falling" and "Ten Miles in Different Days"

3. Weather forecast:

1) Purpose: If we can predict the weather in the near future, we can make all kinds of preparations as early as possible, make full use of favorable weather and avoid and prevent the harm of unfavorable weather.

2) Content: It is necessary to explain the rain or shine, wind, temperature and precipitation in one day.

3) Reading satellite cloud pictures: (textbook P46) Green means land, blue means ocean, and white means cloud areas (the whiter the clouds, the thicker the clouds,

Generally, it is a rainy area. (4) Common weather symbols: (textbook P46) Searching for regular memory. Fill in the blanks or look at the pictures. 5) Representation method of wind: wind power (the strength of wind, with 0~ 12*** 13). Signs and directions of the wind.

Temperature and its distribution in the second quarter

One,

What is the temperature?

1) What is temperature? In a day, the temperature of the atmosphere is called temperature, and the unit is degrees Celsius.

2) Temperature measurement: 3-4 times a day (Beijing time 8: 00, 14: 00, 20: 00, 2:00)3) Description of temperature: daily average temperature: the average value of temperature observed at different times of the day; Monthly average temperature: 1 average value of monthly average daily temperature; Annual average temperature: the average value of monthly average temperature in a year. Second, the change of temperature:

1) Daily maximum temperature and daily minimum temperature: (See Figure 3. 12) The maximum temperature on land appears at 2 pm, and the minimum temperature appears around sunrise.

2) Monthly maximum average temperature and monthly minimum average temperature: the monthly average maximum temperature in the northern hemisphere appears in July, and the average minimum temperature appears in 65438+ 10. Southern hemisphere facies

Anti. 3) Temperature annual range: the difference between the highest monthly average temperature and the lowest monthly average temperature in a year. The greater the annual range, the greater the annual variation of temperature, and vice versa.

4) Characteristics of temperature change: different latitudes lead to different temperatures: the lower the latitude, the higher the temperature, and vice versa. Results: Tropical (high temperature and hot throughout the year, with little change) temperate (four distinct seasons, with significant change) cold zone (extremely low temperature throughout the year).

5) Drawing the temperature curve: make clear the meaning represented by the horizontal axis and the vertical axis.

Similarities and differences in the shapes of temperature curves in the northern and southern hemispheres: the northern hemisphere: wave crest type; Southern hemisphere: trough type. temperature distribution

Horizontal distribution: expressed by isotherm. (Textbook P52, Figure 3. 15)

1, isotherm definition: connecting points with the same temperature at the same time with lines on the map is called isotherm. (The principle is the same as contour line) 2. Characteristics of isotherms:

1) isotherm is closed, and the center temperature is lower than the surrounding temperature, forming a low-temperature center, otherwise, forming a high-temperature center. 2) On the same isotherm, the temperatures at all points are equal.

3) Difference between isotherm density and horizontal temperature: The denser the isotherm, the greater the temperature difference, and the thinner the isotherm, the smaller the temperature difference. 4) The temperature difference between two adjacent isotherms is equal.

(2) Vertical distribution: the temperature decreases vertically upward.

Vertical distribution characteristics and its influencing factors

Latitude factors: low temperature and high temperature, high temperature and low temperature.

(Read Figure 3. 17, it can be concluded that the temperature is the highest at the equator and its vicinity, and the temperature gradually decreases from the equator to the poles. The main reason for the change is latitude.

Differences in solar radiation. The areas where the annual average temperature is higher than 20 degrees Celsius are mainly distributed between the Tropic of Cancer and the land below-10 degrees Celsius.

Teaching plan exercises of the whole class courseware in grade one summarize the historical geography of mathematical English in China.

This area is mainly distributed in the polar circle. )

Distribution of isotherms in the northern and southern hemispheres: From north to south, the value of isotherms in the northern hemisphere gradually increases, while that in the southern hemisphere gradually decreases. 2) Land and sea factors: in the same latitude zone, the land temperature is high in summer and the ocean temperature is low; the opposite is true in winter.

3) Topographic factors: the temperature in mountainous areas decreases with altitude, and the temperature decreases by about 0.6 degrees Celsius per altitude 100 meters. 4) Man-made factors: human beings emit a large amount of greenhouse gases such as carbon dioxide into the atmosphere, causing the greenhouse effect.

The third quarter precipitation and precipitation distribution

One,

What is precipitation?

Precipitation: Rain, snow, frost, dew and hail falling from the atmosphere are collectively called precipitation (natural precipitation). There is also artificial precipitation. Rainfall is the main form of precipitation. Second, the distribution law of precipitation

1, expression: annual precipitation of the sun and the moon. You can draw a precipitation histogram and read it. Reading the histogram of precipitation, we want to get the seasonal variation of precipitation, which mainly depends on two points: (1) whether the precipitation distribution is even in the four seasons of the year, and (2) which months the precipitation is concentrated in and which season the precipitation is less.

2. Distribution law of global precipitation: as shown in Figure 3.2 1, the main factors affecting precipitation.

(1) There is a lot of precipitation near the equator, and the annual precipitation is more than 200 mm Due to the high temperature in the equatorial region, the airflow rises all year round, which is easy to cause rainfall, so it is rainy. From the equator to the poles, the annual precipitation shows a decreasing trend. The reason is that the temperature at the poles is low and the airflow sinks all the year round, making it difficult to form precipitation. To sum up: latitude position: it is rainy in the equatorial region and less in the polar region.

(2) Near the Tropic of Cancer, there is more precipitation on the east coast of the mainland. There are plains in the middle and lower reaches of the Yangtze River, known as the land of abundance, and there is less precipitation on the west coast, which is distributed in the Sahara desert, the largest desert in the world.

To sum up: the land and sea location near the Tropic of Cancer: the east coast of the mainland is rainy, and the west coast of the mainland is less rainy.

In temperate regions, there is more precipitation in coastal areas, such as Beijing on the east coast of Eurasia, which is rainy in summer and London on the west coast, which is humid all the year round. There is little precipitation in the interior, and there is Taklimakan Desert, the largest desert in China.

To sum up: the land and sea location in temperate regions: it is rainy in coastal areas and less in mainland areas. (3) The dry and rainy poles of the world: Atacama Desert and Kilapanchi. Reason: Due to topographic factors, Kilapanchi is located on the south slope (and windward slope) of Himalayan Mountains, which is conducive to the rise of warm and humid air. Rainfall is mostly in topographic precipitation, with less leeward slope. To sum up: mountain (or terrain) factors: windward slope is rainy, leeward slope is less rainy.

Section 4 World Climate

First of all, regional differences in climate:

1. climate: the average weather conditions in a place for many years. Generally speaking, the meaning of (a year) 2 The difference between weather and climate:

(Requirements: Be able to make a clear judgment on a sentence, whether it belongs to weather or climate)

Distinguish the weather

climate

Focus on a certain period of time (short time, such as a few days) for a year, a few years or more.

Intrinsic characteristics

Temperature, humidity, wind, precipitation, etc. It's just the change of temperature and precipitation.

changeable

Generally, there is little change.

climate

Influencing factor temperature

deposit

The higher the latitude, the lower the temperature, the lower the latitude and the higher the temperature.

There is more precipitation in the equatorial region and less precipitation in the polar regions.

P60 Figure 3.24 Land and Sea Location

In winter, the land temperature is low and the sea surface temperature is high. In summer, the land temperature is high and the sea surface temperature is low.

There is little precipitation on the seashore without sea.

In summer, the rocks on the shore are very hot and the temperature in the river is very low. Terrain (terrain factor) temperature decreases with the elevation. The windward slope is rainy (mostly in topographic precipitation), and the leeward slope is rainy.

P60 Figure 3.25 Beggars and Peng Qi

3. World Climate Types and Distribution (P58 Figure 2.23)(P59 two tables)

It is enough to judge which climate type it belongs to according to its characteristics. Second, the main factors affecting climate 1, factors and laws 2, factors and reasons

(1) Latitude position:

A: Temperature: Direct sunlight is obtained in low latitudes (that is, tropical areas), and the higher the solar heat, the higher the temperature; At high latitudes, the oblique reflection of the sun is obtained, and the solar heat is less and the temperature is low.

B: Precipitation: The temperature in the equatorial region is high and the hot air rises. When it meets cold air, it is easy to form clouds and cause rain, so it is rainy. Close to the polar regions, the temperature is low and the gas sinks, making it difficult to form clouds, leading to rainfall. (Equator and polar regions are more obvious) (2) Land and sea location:

A: Temperature: Because of the different physical properties of land and ocean, land absorbs heat quickly and releases heat quickly; On the contrary, the ocean absorbs heat slowly and releases heat slowly. Therefore, in the same latitude area, the land temperature is high and the ocean temperature is low in summer; On the contrary, in winter, the temperature on land is higher than that in the ocean. (Example: When winter comes, the temperature drops gradually, and the river is prone to fog)

B: Precipitation: there is more precipitation near the ocean and can be affected by the moist airflow of the ocean, and less precipitation far from the inland of the ocean. Sea breeze is not blown all the year round in the area near the sea, and there is little precipitation.

(3) Topographic factors:

A: Temperature: For every increase of 100m, the temperature will drop by about 0.6 degrees Celsius.

B: Precipitation: On the windward slope, the warm and humid airflow rises, and it is easy to form clouds when it meets the cold air above, causing rainfall; Leeward slope does not have this advantage, cold air sinks and the temperature drops, which is not suitable for clouds and rain, and there is little precipitation.

(Example: World Rain Pole: Kilapanchi is located on the south slope (windward slope) of the Himalayas, which is easy to form topographic precipitation and has the most precipitation. )